1. Technical Field
Exemplary embodiments of the present disclosure are directed to a digital exposure apparatus and a method of exposing a substrate using the digital exposure apparatus. More particularly, exemplary embodiments of the present disclosure are directed to a digital exposure apparatus improving an accuracy of a pattern and a method of exposing a substrate using the digital exposure apparatus.
2. Description of the Related Art
In general, to form a metal pattern including signal lines and a thin film transistor (“TFT”) which is a switching element of a display substrate, a metal layer and a photoresist layer are sequentially formed, and a mask corresponding to the metal pattern is disposed on the photoresist layer.
Then, light is irradiated upon an upper surface of the mask so that the photoresist layer may be exposed and developed. Thus, a photoresist pattern corresponding to the mask may be formed. The metal layer may be etched to form the metal pattern. When the metal layer is etched, the photoresist pattern functions as an etch stopping layer.
When a display substrate has a plurality of differently shaped metal patterns, a plurality of masks corresponding to the number of the metal patterns is required. In addition, if the shape of the metal pattern is changed, the shape of the mask should change correspondingly so that a new mask may be fabricated. Since the fabrication cost of a mask is relatively high, the manufacturing cost of the display substrate may increase.
Alternatively, a digital exposing apparatus providing a plurality of beams to a substrate without the mask may be used. In a digital exposing apparatus, beams may be independently turned on or off to selectively provide beams to the substrate. Thus, a desired photoresist pattern may be formed on the substrate.
An area on which the light from the digital exposing apparatus is incident is quite limited, so that either the digital exposing apparatus or the substrate needs to be displaced to form the photoresist pattern on a large-size substrate. To improve productivity of the substrate, the digital exposing apparatus or substrate may be displaced at a relatively high speed.
A cross-sectional shape of the beam provided to the substrate is ideally a circle. However, when the substrate is displaced at a relatively high speed, the cross-sectional shape of the beam may be distorted, decreasing the accuracy of the pattern.